Two Videos Below:Video 1- How to make the molding material.Video 2- How to use the molding material. Making and molding for duplication is a great way to replicate parts. It is a process that has a very long history and technology has made the molding and casting of many materials possible. And each process comes with some positive aspects and some negative ones. One of the most successful products has been the use of RTV Silicone, a two-part flexible elastomer that can be catalyzed by either a tin or platinum reactant. Mixed 1:1, and poured over the part to be copied, the results are typically excellent. It provides fine detail, de-molds fairly quickly, can be used to cast many times, generally requires no release agent, has high heat tolerance, and it is dimensionally stable. But, the advantages come with high cost, limited shelf life, and of course, it is not reusable. Once you are finished with the mold it is discarded. And urethanes are possibly the next most popular with casting enthusiasts. Despite the vast array of materials, none are really reusable. They are all relegated to the trash bin when they fail to perform satisfactorily or are no longer needed. But, I do have an alternative for your consideration. It is a reusable, inexpensive, and very functional molding material based on gelatin as the elastomer, glycerin as the plasticizer, and water to form the colloidal suspension. I have been using this molding material for several years and it was initially developed to secure cover slips to microscope slides. At first I used agar, but that was expensive and difficult to find locally. So, I tried gelatin and glycerin and it worked really well. I noticed that when poured on a flat surface, it formed a flexible film that acted like rubber, had a melting point well above room temperature, and could form a mold. So, I used it for small items and general castings. But recently, I decided to try and make larger and more complicated molds and cast with epoxy resin, paraffin wax, polyester resin, and Plaster of Paris. The results are promising but there is still a lot of experimenting to do. But, I think that by posting the process now, some of the readers will be able to add their information in the comments section and we can all work together to make a better process. The basic formula is shown in video 1 and it is very easy to make. Initially, the first time it is formulated, a stovetop is best as continuous stirring is required. It can be made in a metal pan as well as in Pyrex containers or glass beakers. Containers are easily cleaned with hot water. Once the elastomer is made, it can be reheated in the microwave oven using short times until you learn how much time is needed. For small batches, (40 ml), I use about 10 seconds. (In microwave acceptable containers, not metal!). The mix does not require boiling and seems completely dissolved at around 160 Fahrenheit, (71 Celsius). It sets to a rubber-like elastomer at room temperature and remains flexible. Its actual melting point seems to be about 130 F. The flexibility can be varied by using less glycerin for a firmer gel, and more for a softer material. Without using a gelometer, my best guess is that it can vary from about a 15 Shore A to a 40 Shore A, and that compares favorably with Silicone RTV. In video 2, actual molding results are demonstrated with the advantages and some downsides as well. I recently discovered some commercial products that are reusable but I have not investigated them yet. I mentioned in video 1 that chocolate can be cast as well but that process requires a higher quality glycerin. The material sold in drug stores is not as pure as what is called food grade glycerin. That is 99.9 % pure. It may be available in markets locally, but is definitely available online.Basic Formula: 20 milliliters room temperature water. 4 grams unflavored gelatin. 24 milliliters glycerin. Mix as demonstrated in video 1. I have been using a 10 times batch that is about 450 milliliters. Please enjoy the videos and comment! Ken…

Well, it did work! I used paraffin wax and 1/2 of a red crayola crayon for the color. I did expect the dimension change as that is the nature of wax. I did also chill the mold. So, it is another use for this mold material. Try it!

wow Ken that's so cool.just wot I need I haven't got a lot of money but I love moulding an experimenting an I wont to make some stuff for a market stall I was looking at that other reusable stuff but your stuff looks like it could even be the same proses its grate thanks so much for your info ken you made me a happy little vegimight that's Australian for very happy.

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Ken

1/26/2014 07:40:02 am

Hey Dave,
Thanks for the comment and I hope that the process works as well for you as it has for me. If you start with small quantities it should not cost very much. Best of luck, Ken

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Jackie

3/8/2014 04:01:41 pm

Once I ave made the gel is it ok to use as a chocolate or sugar paste moulds? x

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Ken

3/9/2014 12:44:21 am

Hi Jackie,
Yes, you should be all set to use in any molding procedure. You may have to chill the mold if the chocolate is really hot. But, I have successfully cast chocolate without chilling. Thanks for the comment and question. Ken.

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Sindhu

3/25/2014 03:55:52 pm

Hi Ken,
That sounds great ! Can you suggest a vegan substitute for gelatin in this recipe ?

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Ken

3/26/2014 01:31:30 am

Hi Sindhu,
Gelatine is an animal by-product and as such has no vegan equivalent but there are some possible substitutes. Copy and paste the link for some candidates. I have not used any of the materials listed in this application but I have used Agar as a biological growth medium. That would be my first choice for experimentation. If you are successful, let us know. Thanks for the question, Ken.
http://www.wikihow.com/Find-Gelatin-Substitutes-for-Vegetarians

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Nicole

1/31/2015 04:38:37 pm

There is a product you can get here in Australia called gel-it-in, which is a gelatine product made from a corn derivative, so is vegetarian safe

commsnake

6/15/2014 04:57:49 pm

I've used a firmer mix than this for a year or two for casting terrain/bases for wargaming. A few drops of mouthwash or screen wash stops any problems with mold , i just keep my moulds in a box in the garage till I need to cast again. So far good after a year, with 20+ reuses

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nubair

7/21/2015 03:42:51 am

i made it but it melts outside refrigerator. .. can u guide me plz

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Ken

7/21/2015 08:41:28 am

Hi Nubair,
If the gelatin and glycerine are used in the ratios described, the melt temperature is about 130 F or 55 C. (20 ml water, 4 grams gelatin, and 24 ml glycerin). Unless it is incredibly hot there I would suspect that the amounts may be wrong. Hope that this helps, Ken.

Becky Hall

6/29/2016 11:48:57 am

Hi can you tell me what ratios and ingredients and process you use?

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Ken

6/29/2016 03:37:47 pm

Hi Becky,
The ingredients are listed at the end of the write up and the easy process is covered completely in video one. Thanks, Ken.

marcus

6/22/2014 06:30:53 pm

hi, Ive been looking for a reusable moulding material for a while now... that is relatively cheap to make! I see you re-melt the material in the microwave... can it be re-melted in a pan on the stove!? because I want to use larger amounts.
Thanks...Marcus

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Ken

6/23/2014 01:46:49 am

Hi Marcus,
Because this material has a relatively low melting point it can be re-heated on the stove using low temperature to avoid scorching. Even better would be a double boiler and let the water heat the material. Good luck and thanks for the comment. Ken.

My question is could you use this for a face mold? I want to make a mold of my face but if the temp is to high then I need a alternative

Reply

Ken

7/7/2014 08:23:59 am

Hi Mike,
There are two problems with using this as a body part mold: The temperature is 30 to 40 degrees above body temperature and the mold would probably be too flexible without support. I would suggest an alginate life casting material that is readily available. Just Google! Thanks for the question, Ken.

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tracey

7/15/2014 02:24:21 pm

hi bill
do you have a utube site with these videos
great work love it

Reply

Ken

7/17/2014 02:09:35 am

Hi Tracey,
I am working on putting some form of my videos on YouTube. It has been on my "to do" list. Thanks for the comment! Ken

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marisa robson

7/28/2014 03:47:50 am

gonna try this right now! thanks so much for posting ken.

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marisa robson

7/28/2014 04:54:10 am

wow it's so fast!!!! messed up my first batch completely somehow... put in way too much gelatine and the mold came out opaque... happy accident though because i REALLY like the results... smooth as glass and strong as silicone rubber.

second batch was too loose (what the hell is going on with my scale)

third batch i think i got roughly like yours was... in the freezer now.... but i think i may load it with more gelatine to try and get it like the first :) I'll let you know how the castings come out.

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Ken

7/28/2014 08:37:16 am

Hi Marisa,
The good thing about this process is that it can be varied depending on the need as you have discovered. I hope that you have continued great results and projects. Ken.

marisa

7/28/2014 09:03:21 am

yip that became quite clear right away... at least in terms of the mould... i've filled a couple with clear epoxy ... gonna let them cure for about two days because it's winter here... i'm really hoping they come out glass clear... if they do, this will be my permanent moulding method :)

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tracey

7/28/2014 10:08:07 am

hi ken if i make the mix and find out its not hard enoiugh ,can it be melted down and have some more gelatine mixed in with some water while its liquid form ,to firm or would this ruin it

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tracey

7/28/2014 10:10:26 am

hi again ken , i have seen some people use your mix but with added honey what would the honey do

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Ken

7/29/2014 02:47:40 am

Tracey,
I see no advantage to adding honey, and, as it has sugar, it will tend to become moldy without refrigeration. Makes no sense to me. Ken.

Deborah

11/2/2016 01:52:29 pm

Hi Tracey and Ken,
Loved the video, thanks Ken. Honey has antibacterial properties, but whether it would prevent mold from developing would be interesting to know. Honey also has a high viscosity so wondering if adding it might require adjusting the ingredient ratios.

Ken

7/29/2014 02:44:51 am

Hi Tracey,
I would take a small portion of the to soft mix and stir in the added gelatin without added water and let it swell. Then reheat the small portion with stirring to dissolve. Then add this to the main mix. Ken.

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tracey

8/3/2014 05:11:30 pm

thanks so much ken , i i have just got hold of some Professional strength 300 Bloom gelatine , could you give me the measurements if using this stronger geltatine as i know i have to use alot less than normal
thanks again

Ken

8/4/2014 09:03:15 am

Hi Tracey,
The gelatin that I used is rated at 225 Bloom so the 300 Bloom will provide a stiffer gel than the 225. The Bloom number is simply a test to find how deep a 1/2 rod will penetrate the hard gel. They measure how the rod separates the gel and how far it enters. I would guess that you could use the same proportions and you will get a stiffer gel. If it is too stiff, try a 25 % reduction of the 300 Bloom. That should give a reduced stiffness but it may be what you desire. But, please let us know how it works for you and we can all learn. Ken.

marisa

7/29/2014 11:46:29 pm

well that was weird... demolded clear epoxy last night - usually comes out water clear but it was ... milky? waxy? it almost looks like something in the mold (gelatin or glycerin or moisture actually leeched into the epoxy)

anyhoo... heartbroken a little... i lurve this goop so i'm going to try a mix just with water and another just with glycerin... wish me luck :)

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Ken

7/30/2014 02:40:26 am

Hey Marisa,
This is one experiment that I did not do as I usually color my epoxy, but I think that your observation is important for other users. Did you try buffing to see if it is a surface problem? Was there a possibility of water or condensation when you poured the epoxy? What happens if you pour a second copy? Does the same problem exist?
I have set-up some experiments using a true casting epoxy and a clear adhesive epoxy to see if I get the same problem. Let's see if we can determine what is happening to inform other users. Don't be heartbroken yet! Ken.

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marisa

7/30/2014 04:33:52 am

haha thanks ken... but in my world heartbroken simply means adjust and carry on :)

I agree that the observation is important ... i'm kinda hoping we can all find a solution together, worst case scenario being... i'll just try painting a thin caulking layer onto the original before bunging in the jelly ... the white cloud happened in both my molds (i did one according to recipe and one with pretty much equal parts water / gelatin) ... it wasn't surface - it went about two mm in below the surface... i actually cut some of the resin off the piece just to see... really it almost looked as though it had been cast in a white plastic that had transparent bits swirled through it.

I didn't buff it because on clear resin that tends just to make it frosty while glazing it covers a multitude of cock ups... but no... it just became a shinier waxy white lol

it actually seems to have dyed the resin! so weird.

I wondered about water... i doubt it though... yes the mold was dry, the mold also had a mold release on it... and usually in contact with moisture (yes i've been there), epoxy will bubble and even foam... but this, i've never seen before... which is why i thought it could be because of the glycerin.

Re second copy... i'm going to do that... but i want to wait a few days say about three days ... and then i'll cast another piece... maybe the material needs to stabilise in some way.... although it looks and feels pretty stable.

I have set-up some experiments using a true casting epoxy and a clear adhesive epoxy to see if I get the same problem. Let's see if we can determine what is happening to inform other users. <---- awesome :)

here's the weirdest thing of all though... looking at the resin IN the molds it looked completely clear... the minute i lifted it OUT of the molds... the white appeared... the surface of the piece is in no way damaged... fine hairline imperfections picked up by the jelly were on the moulded piece... just in white o.O

i'd love to know what happens with yours

Reply

Ken

7/31/2014 08:40:17 am

Marisa,
Here are the results so far: The adhesive epoxy, (Devcon, 5 minute cure time) had no surface imperfections and was perfectly clear.I used no mold release on this. The true casting resin (EasyCast, 24 hour cure time was a bit different. On one sample I used mold release (Silicone as in the video) and the other no mold release. The results were that both were slightly clouded but not white or discolored. I have a very general hypothesis based on these preliminary observations. Glycerine is a polyol or sugar alcohol and may be able to penetrate the epoxy before being fully cured. In the adhesive mold there was only 5 minutes for the cure so it did not have time to penetrate the surface. There is more to do but that is what I have so far. Ken.

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marisa

7/31/2014 09:48:05 am

Excellent, Ken - thanks so much for sharing! I'm a little snowed under workwise at the moment but I'll make one from pure gelatin and see if i get better results- i'll also cast in some 3 hour cure time polyurethane and see how that comes out... here's to ongoing collaboration!

M :)

marisa

8/2/2014 09:29:17 am

hi ken... just cast a couple of experiments - firstly my two molds from the other day (they've had a couple of days to get dryer) and a brand new mold made of nothing but gelatin just enough water to make the gelatin ball before melting it... my god those edges are crisp it made an absolutely awesome mold.... but the resin is turning cloudy in it... go figure... it's been in there for about two hours and i can actually see it happening this time.

maybe more glycerin is the answer.... maybe oil? olive or whatever... i'll let you know as soon as i have some answers :)

m

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Ken

8/3/2014 09:12:00 am

Hey Marisa,
I also did some tests based on your comments about the gelatin only mold. I poured some epoxy on a thin film of water in one test, and onto a silicon sheet with some perforations with water underneath in the second test. In both, there was significant clouding. The one with the perforations was clouded where the holes were. And, although epoxy is hydrophobic, there appears the be serious interaction with moisture. The only remaining candidate would be the mold release if you used any. I guess what is perplexing to me is that I re-examined my earlier dyed casts and there is no evidence of surface contamination. I am truly at a loss to think of other possibilities. Ken.

Reply

marisa

8/3/2014 11:34:42 am

Hi Ken,

yip i've also pretty much come to the moisture conclusion... so sad. love those molds so much.

I'm going to go ahead and try with LOTS of glycerine (because it attracts moisture, the internet tells me... which means MAYBE it'll keep it away from my epoxy) plus i'm going to leave those moulds be for about three weeks this time... and then try again lol (never say die)

Reply

marisa

8/30/2014 09:14:49 pm

hiya ken,

just to report back... i've let the molds sit for a while and tried another casting in them on thursday night... yip, the 24 hr set resin still turns cloudy... eh well... it was fun but no banana.

i think i also mentioned having made moulds with almost equal parts of gelatine and water? also with very little glycerin... those turned hard... might be interesting to make stuff out of that material it's surprisingly durable :)

anyway... thanks again for your post and for sharing your info

Reply

marisa

8/30/2014 09:15:00 pm

hiya ken,

just to report back... i've let the molds sit for a while and tried another casting in them on thursday night... yip, the 24 hr set resin still turns cloudy... eh well... it was fun but no banana.

i think i also mentioned having made moulds with almost equal parts of gelatine and water? also with very little glycerin... those turned hard... might be interesting to make stuff out of that material it's surprisingly durable :)

anyway... thanks again for your post and for sharing your info

Reply

marisa

8/30/2014 09:15:11 pm

hiya ken,

just to report back... i've let the molds sit for a while and tried another casting in them on thursday night... yip, the 24 hr set resin still turns cloudy... eh well... it was fun but no banana.

i think i also mentioned having made moulds with almost equal parts of gelatine and water? also with very little glycerin... those turned hard... might be interesting to make stuff out of that material it's surprisingly durable :)

Excellent videos, Ken. I watched a video on Youtube this morning and the guy didn't use any water. Just the glycerine, and gelatine. Have you done a batch without water? If so, is there any difference?
Also, I see you have the automobile repair resin in the background of video two. Was there any success with that product? Thanks!

Reply

Ken

8/11/2014 09:32:16 am

Hi Chris,
The material made without water tears very easily and is not really suitable for mold making. It is used for special effects. The water adds some hydrogen bonding to provide a stronger and more flexible colloid.
The resin is a polyester and is cured with methyl ethyl ketone peroxide that comes with the resin and is designed to work well with Fiberglas. It is a good casting polymer as well but is amber, not clear. It is also more exothermic and the mold should be chilled before pouring the resin. Thanks for the questions, Ken.

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Chris

8/11/2014 02:15:22 pm

Thanks Ken! Excellent to know about the water, and being able to chill before using the urethane and resin that give off heat..
I wondered how the polyester resin worked as I've have very little success with that type unless I was doing car repairs. Even with silicone molds and pressure casting, I rarely get a decent cast (sticky).

tracey

8/12/2014 03:54:04 pm

hi bill
do you have a recipe to make food grade silicone
i would love to make my bigger molds in silicone
and leave smaller ones to the gelatine molds
anyone have any recipe for food safe silicone would be grateful regards tracey

Reply

wendy

8/17/2014 10:29:14 am

hi there everyone , i too would love to have a recipe to make my own silicone moulding material thats pourable , made with cornflour and silicone
anyone have the method ?

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WENDY

8/27/2014 10:16:38 am

hi ken any chance you hAVE iddeas about my previous msg hi there everyone , i too would love to have a recipe to make my own silicone moulding material thats pourable , made with cornflour and silicone
anyone have the method ?

Reply

Ken

8/28/2014 03:31:38 am

Hi Wendy,
I am making an assumption that you are referring to oogoo, which is 100 % silicone caulk and cornstarch. The key is "pourable" and that requires a suitable solvent for the silicone. Most of the solvents used are flammable like xylene and lighter fluid "naphtha". I have had some success with this approach but it requires some experimentation. Here is a link to copy and paste to get you started. Good luck and let us know how it works for you. Ken.
jamesgregson.blogspot.com/2012/12/pourable-oogoo.html

I have been casting with easy cast for around five years now and tried this out before. No luck. I tried using different oils, chilling, and even fillers with no luck. I have even tried out melting fishing lures in the past, and that just turned out weird. Keep up the hard work everyone, and maybe someone will stumble on a simple home made molding material for resin eventually:) appy crafting!!!

Reply

Ken

8/27/2014 08:49:12 am

Hello,
I am not sure why you are having problems with the EasyCast resin as I have used it successfully many times. With the silicone spray release I have seen no problems without chilling as the exotherm is very low as it is a slow curing epoxy. I wish that you had experienced a better result. Ken.

Have you tried this mold material with urethane casting resins?
Does the moisture in the mold have negative effects on urethane resins?
Thanks for your response

Reply

Ken

8/30/2014 08:56:40 am

Hi Edward,
I have not cast any urethane as it has been some time since I have had any to try. However, the water is bound to the gelatin and not really available to interfere so it should work well. Try a small sample and let us know. Thanks, Ken.

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Edward

8/29/2014 09:40:26 pm

1) Can you scale your formula up to produce a gallon of mold material without a problem?

2) How many pulls do you estimate you can get out of a mold if the casting item has no undercuts only horizontal and vertical walls?

3) Any ideas on what to use as a casting resin to produce a semi-ridgid (moderately flexible) reproduction of an architectural trim piece approximately 4 inches wide, 36 inches long and 1/4 inch thick?

Any ideas will be appreciated ,,, thanks

Reply

Ken

8/30/2014 09:02:56 am

Edward,
The formula can be scaled up easily but I would do it in a couple of batches.I have not done more than 20 but I think that it may be capable of more but I am not certain as to the number of pulls. For a semi-rigid polymer I think that I would use a polyester and maybe use a Fiberglas filler. Ken.

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Edward

8/29/2014 09:50:12 pm

Couple other things:

1) Since the mold is made with gelatin will it attract insects like ants during storage?

2) And any idea of how long the shelf life might be for a mold when stored at room temperature in a dark place like a closet?

3) And do the molds need to be lubricated to prevent drying out during storage ( vegetable oil - baby oil ) ??? - Do you think shelf life might be at least couple weeks or months?

Great videos and information ... Thanks in advance for your response.

Reply

Ken

8/30/2014 09:08:01 am

Edward,
I have had a large sample out in the open at RT all summer and there has been no insects, mold, or degradation. The water does not leave the material but I would cover the container with some Handiwrap to protect it just in case. Thanks for the comments, Ken.

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Edward

8/30/2014 12:49:15 pm

So, no extra lubrication is needed during storage ... that's great.

Edward

8/30/2014 12:52:02 pm

I purchase some gelatin and glycerin today and I plan to give it a try before the week is up.
I will have to let you know how it all works out.

Thanks again for the great information you posted. I really helps a lot.

Edward

9/1/2014 11:34:43 am

Hello Ken,

I tried to make up a batch of Gelatin Mold making material today.

I scaled the recipe up to make approximately 5 cups using three (3) 6oz bottles of glycerin and 18 envelopes ( 7 grams per envelope ) of Knox gelatin with just over 14 onces of water.

It was hard to tell if I had the heat up high enough to properly blend the mixture, I was trying to make sure I keep it below boiling point.
Do I need a cooking thermometer?

The mixture produced a significant amount of foam floating on top.
I thought the cooking pan was filled foam until I poured it into my clear plastic container and saw that there was about an inch of nice yellowish brown gelatin with only about 1/4 inch of foam on top.

I heated the mixture on low heat for about 10 minutes hoping the foam layer would be reduced over time, but it really didn't happen.

Is that much foam an indication that something went really wrong during the process?

I won't know just how firm the mold sets up until in the morning … letting it set over night.

Love to hear your comments on the foam and the thermometer.

Thanks a lot.

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Ken

9/2/2014 09:10:17 am

Hi Edward,
The foam is actually entrapped air bubbles caused by stirring. Because the mix is so viscous, it holds onto the foam. You could try scraping off the foam and re-heating it in the microwave to see if the bubbles collapse.I have thought about a defoamer (wetting agent) but have not tried it yet. Even an alcohol might work but it needs to be tried before I recommend it. No thermometer needed if you stay below the boiling point, but, a thermometer wouldn't be a waste of time either. Your choice. Thanks for the questions, Ken.

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Edward

9/2/2014 12:59:55 am

The mold came out nice and firm ... just has foam layer on top.
Is there a way to prevent the foam layering? Or should I just try scooping it off and discarding before pouring the mold?

Wonder if you could use and old crock-pot for this? Would the temperature get warm enough?

Thanks

Reply

Ken

9/2/2014 09:15:04 am

Edward,
Try pouring slowly down the inside of the mold to minimize air bubbles. This usually works. If the foam doesn't cause a problem I usually disregard it. A crock pot gets warm enough but cycles too much and is a bit slow. And, if you remove the cover, the temperature goes down to much. Thanks, Ken.

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Edward

9/7/2014 07:29:46 am

Just wanted to give an update.
The mold worked great even with the layer of foam of top.
Next time I will try to skim the foam off before pouring the mold.
Thanks a lot Ken for posting this information it has been a great help.
Thanks again.

adam

11/7/2014 05:54:28 am

is glycerin necessary

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Ken

11/8/2014 01:30:05 am

Hey Adam,
The glycerin is a plasticizer and provides the flexibility in the formulation. If you make the mix without glycerin it will harden to a solid. There may be some value to this for some uses but not for reusable and flexible. Thanks for the question, Ken.

Thank you so much for the amazing detail and explanation!! Going to make a few small molds for fondant/sugar work. This will be perfect!! Just for fun- I plan on tinting the mold material. I'll def update with results ♡

Reply

Edward

1/10/2015 07:47:30 am

Hello Ken,
I tried another batch of your gelatin mold formula this weekend.
I made some castings using polyurethane casting resin and it worked great!
I finally got a mold without the foaming bubbles. I think I may have had the heat up too high last time.
Again, thanks so much for sharing.

Reply

Ken

1/11/2015 01:54:59 am

Hi Edward,
That is good news as we have had questions about polyurethane in the past that I had not tried. Thanks for adding to the conversation and providing your results. Bubble free? Great! Thanks, Ken.

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Nicole

1/31/2015 04:50:38 pm

I noticed in your video you said the plaster was falling apart. I was looking at using this mix to experiment with plaster molds for kids.
Do you know if it was the plaster mix you used, or if there is some reaction with the mold that made the plaster crumbly?

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Mark

2/9/2015 08:47:54 pm

Thanks for the great videos, they help alot.

I'm thinking about buying the ingredients to make some molds. Is it possible to make a two-part mold with this? I was thinking it would melt the first half when adding the second half

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Ken

2/10/2015 08:23:46 am

Hey Mark,
Great question and you are correct that the two halves would be easily combined. It may be possible to chill the first half and pour the second part when it was cool enough to still pour and a silicone spray used as a release agent. But, this is a stretch at best. My suggestion would be to cast the item completely and then cut the parting line. As demonstrated in the video, the material cuts easily and can be put back together and held with rubber bands. You could also cast some registration pins to make the alignment better. If you come up with a solution be sure to let us know. It would be a nice step forward. Thanks, Ken.

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Mark

2/11/2015 10:52:53 am

Thanks for the speedy reply Ken.

Im pretty new to casting, i use oyumaru for molds but my alumilite 15 min demold resin heats up and puts bubbles in the mold.

Would the same thing happen with this glycerol mold? Do you know what temperature the mold is rated to?

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Ken

2/14/2015 02:23:16 am

Hey Mark,
This formulation has a lower melting point than oyumaru. It is serviceable up to around 135 F. But by chilling it I have cast epoxy and polyester with no problem.

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Valerie

3/9/2015 08:12:24 am

Ken, I thank you to the moon and back for your expertise. I happen to have the gelatin and glycerin products and I will try making the recipe for food safe molds.Would you happen to know the durability and life expectancy of the molds? I'm in the cake design industry and I use a lot of silicone molds that are suppose to be food safe. However, I stumbled upon a website where a toxicologist stated that all silicone including FDA approved food safe silicone is actually not safe at all. The toxicologist claims to have patients suffering from cancer, and several other life threatening ailments directly related to silicone. She also stated that the silicone has attached itself to the patients DNA. Also, I would like to know if you have any other food safe mold recipe's? Thank you again for blessing us with this information. Valerie

Reply

Ken

3/10/2015 02:44:05 am

Hi Valerie,
I have used open molds more times than I can count without problems. For closed molds like the alien or Santa Clause I have used less frequently so I really do not have a number. However, with care, this mold material can be durable. You can also experiment with using less glycerine and make a stiffer but stronger mold. Check the comments for more info on glycerine reduction. You can actually make it really stiff and almost hard if you want to. I agree with the questions about RTV but suspect that the catalyst may be the problem which can be tin or palladium based. If you get a chance please send a link to my email on the article to: ken.quast@gmail.com. Thanks for the comments and question, Ken.

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Valerie

3/11/2015 04:41:37 am

Thank you Ken for your rapid reply. I have several objects needing to be replicated that are not heat resistant. How do I go about using your recipe without fear of distorting my objects? Also, I would like to know what is the pot life and demold time? Thank you again, and again. Valerie

Valerie

3/11/2015 08:14:17 am

Hello Ken, I'd like to thank you again for your knowledge and expertise. My next question to you is when do I insert my object into the mixture? Do I allow the mixture to softly chill, then insert the object or do I insert the object while the mixture is in its liquid state? Also, is there a way to prevent the mold from being water soluble and how do you suggest cleaning it? Thank you so much.....Valerie

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Ken

3/11/2015 09:47:57 am

Hi Valerie,
This formula as indicated in the writeup melts at about 130 F (54 C). If the items to be copied are extremely sensitive to heat they may be at risk. But, by chilling the item first and letting the mix cool, the copy can be protected. Reasonably, the viscosity increases as the mix cools and you can wait until it is still pourable. The pot time is dependent on mass but it is similar to the way water would cool. The demold time is again dependent on mass but is fairly short and can be shortened by refrigerating. The mix can be best cleaned by filtering through something like cheese cloth or fine screen. The formula will always have some sensitivity to water even at room temperature when solid but can be used in high humidity without a problem. When I make a mold I generally place the item in a plastic container and pour the mix slowly to avoid included air bubbles and it works well. As mentioned earlier, reducing the amount of glycerine you can get a stiffer mix that is a higher melt temperature. It will depend on how flexible and hard you like it and can tolerate. Less glycerine also reduces the water sensitivity. Hope that this helps. Ken.

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willi

3/15/2015 01:05:19 am

Hello Ken,
First many thanks for your knowledge and expertise. in fact i need to make formula like This but flammable ! This product you know solid alcohol fuel or fuel tablet ! not like sterno gel packed in cans nor hexamine fuel tablet ! It's just like Japanese solid alcohol ( in rubbery tablet form ) which make by agar 1-3 % boiled in water 30 % ,then add 70 % alcohol.
I found that This amount of alcohol( 70 %vol ) doesn't gelled with the remaining water and agar ! So , if i decrease the percentage of alcohol to 40 % combined with 60 % water maybe won't ignite !
sorry for long details ! the qst is : can i make flammable rubbery form like This you explain by adding 50 % alcohol to glycerine - gelatin to becomes flammable rubbery ? Glycerine it self can't flame . so if it can, what is the melting point in this case ? you know melting point of 1.5 % agar gel about 85 C !. Can you help me ?
Great thanks Ken , So happy to send you emails if you interest !
Greetings ,, Willi

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Ken

3/16/2015 03:26:24 am

Hi Wili,
While glycerine is an alcohol it is a polyol, a simple sugar alcohol with a high flash point, > 160 C and a very high autoignition point. But, it is flammable. I tried some quick experiments with methyl alcohol to see if I could lower the autoignition without any luck. I really don't see how this formula can satisfy your requirements. Perhaps a Google patent search for flammable gels wold give some insight. Sorry I was not able to assist you. Ken.

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willi

3/16/2015 09:49:43 pm

Thanks Ken for your effort. Great thanks, maybe will try again with agar adding to gelatine -gylcerin formula then ethyl alcohol may combine with them.
Greetings.. Willi

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Valerie

3/17/2015 10:55:09 am

Hello Ken,
thank you once again for your assistance. Within a very short time I will post the video & pictures of my mold project. Hopefully I explained myself clearly. Thanks again......Valerie

Instead of adding 24 *milliliters* glycerin as per your instructions, I added 24 *grams* of glycerin.

1ml of glycerin may not weigh 1 gm of glycerin!

Easy mistake to make. I just thought I might share :)

nemanja

5/20/2015 06:00:29 am

Hi Ken.
Thanks for sharing! This looks amaizing!
I am wondering can this material be colored in some way? Maybe with food colorants?
I was thinking since I already have molds to cast with this material.
So will food colors have have any effect on final product?
I will check it out and share the result.
Also have you tried to put this material in water (after it hardens)? Do you know what is happening with it in water?
For me this could be interesting for making aquarium props. I will deffinately try and share.

Thank you very much!

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Ken Quast

5/20/2015 10:00:04 am

Hi nemanja,
Yes, the material can be colored with food dye but it may be less brilliant than you may want but worth a try. As far as moisture softening the material, I have not tried yet. My best guess is that depending on the temperature of the water it will re-hydrate. It may take some time but it will be water soluble unless coated with a spray polymer. But, by all means please verify and share with us as we can all learn. Thanks, Ken.

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nemanja

5/21/2015 04:54:46 am

Hi Ken,

Considering water properties of gel I have to make couple of observations.

First, it is negativ bouyent. It sinks. That can be positive or negative depending on aplication.

Second, it is totaly clear in water. From the first moment. Yellowish color is washed right away.

Finaly, after 2 hours there was no change in gel (except color). It was elastic and tough. And shape was remaind.
But after 12 hours it was different story. Shape remaind but elasticity was gone. It was maybe 50% than before put in water. Insead it tands to tear under presure.
It can be that part of the gelatin is being absorbed buy water, because my hands after contact with that water are a bit sticky.

I will try to make another round, but after it is set I will dunk it in some acrilic paint (since I have it arround), and when paint dryes put it in water to see what happens.

I think I have some paint for boats arround somewhere (it is waterprof but not elasic) and have a go with that aswell.

Anyway will share results

Joe

5/25/2015 11:53:01 pm

Ken, this is an awesome tutorial! Thank you for taking the time to do it and post it for us.

I mixed the materials and put a figuine in it. Let it overnight and when I get home tonight I will see how it did. I was unable to find unflavored gelatin and went with orange flavor.

I was thinking to use the same stuff I used for the mold as a casting material, just to see how the mold worls before buying anything else. Do you think that will work?

Thanks!

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Ken

5/26/2015 02:52:11 am

Joe,
It will depend on what is actually in the gelatin package. If there are sweeteners, dyes, and flavors,it may cause problems. But, you are taking the risk and experimenting and that can only be good! Please let us know how it works and maybe include the package contents and brand so we can all learn. Thanks for the comment, Ken.

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Joe

5/26/2015 04:04:12 am

Thanks for the reply Ken. I will update when I play with it. With your mixture, do you think you can use the same thing for the mold as for the casting itself? Like using the same substance for both things.

Ken

5/26/2015 08:24:42 am

Hi Joe,
I don't see any way possible to use this material as both the mold and the casting material. The warm gelatin/glycerin portion will immediately begin to melt the mold causing a mess. Sorry, Ken.

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Joe

5/27/2015 01:19:05 am

Thank you for the reply Ken. I am about to go buy the Gulf Wax to try it. I read you chilled the mold. As for the wax itself, did you let it cool a little bit or did you just poured it right from the pan (or what you used to melt it)? I guess you have to wait some or it would melt the mold, right?

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KEN

5/27/2015 09:52:27 am

Joe,
Wait until the paraffin wax has cooled but is still pourable and pre chill the mold, Ken.

Akshat Jariwala

6/18/2015 05:14:23 am

Hey Ken,
Great job on the mould development. It looks very promising.
I was wondering if you have tried using agar as a binder in place of gelatin or if you think that might work at all.

Thank you for sharing this! Great stuff!

Akshat

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Ken

6/19/2015 02:41:44 am

Hi Akshat,
I have not used agar as it is hard to find locally and usually expensive. I do use agar for bacteria cultures as agar is not digestible by bacteria where gelatin is. So. you will have to try a small experiment and let us know what you discover. Thanks, Ken.

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Akshat

8/3/2015 06:45:29 am

I did try using Agar. Though it does a good job of making the mold. The mold is not very elastic and breaks easily unless handled with care. It also loses water quickly. In a few days, it visibly starts shrinking in size.

The gelatin-glycerin does well. But, I observed that varying the glycerin changes the mechanical properties significantly. In general, a 1:1 ratio worked best for me. Thanks!

Akshat

8/3/2015 06:47:21 am

Correction in the below post:
it was 1:1 ratio of water and glycerin and 10g/L gelatin

kellyzhang

8/5/2015 10:16:25 pm

may i know more details about your products?

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Ken

8/6/2015 02:31:12 am

Hi Kelly,
I have no products to sell or endorse. The information in the videos is designed to help viewers acquire and complete this project. Thanks, Ken.

Ken, I tried the recipe, using Edward's cup measurements, since I don't have a milliliter measure in the house. I found it really difficult to mix the gelatin with the water, and the bits that didn't get wet with cold water would, naturally, refuse to melt.I was able to remove the hard bits, and the material that was left seems very strong. Is there a trick to mixing the water with the gelatin that I can use when I make my next batch?

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Ken

8/25/2015 03:37:36 am

Hi Jonni,
I am not familiar with Edward's cup measurements but I am assuming that it is Imperial measure (Cups and ounces). It does sound like there is a quantity problem as the gelatin should swell after it has been added with stirring to the water at room temperature. Then, when the glycerine is added it will plasticize the mix and gentle heating with completely dissolve the gelatin. So, in Imperial measure the 20 milliliters would be about 4 teaspoons, and the glycerine would be about 5 teaspoons.The measurements are not critical but with less glycerine the mix will be slightly harder and stiffer. But in any event, the gelatin should swell before adding the glycerine. I hope that this helps but it would be worthwhile to pick up a cup measure with milliliters as well. If you have further problems you can email me at ken.quast@gmail.com and I can offer additional assistance. Thanks, Ken.

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Jessica

9/27/2015 02:30:17 pm

would it be possible for you to upload all of your part 2 videos on you tube every time i try to view any of your part 2 videos it will only play a few minuets ( i am using chrome) no issue like this with other videos fro other sources , i have clean browser history cleared my cache etc it is only the part 2 videos and on this site I would love to be able to see the entire process of each project thanks great work!

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Ken

9/27/2015 04:34:12 pm

Hi Jessica,
Actually, it is difficult for me to copy my video and add to YouTube due to my server restrictions. However, I just updated the site to "refresh" and watched it in Chrome with no problem and I have DSL. I also watched it in Firefox and Safari with no problem. Perhaps you can try again as I have not seen this problem in the past 5 years. You might also try starting the video and double clicking on the video to show the play and pause and expand bar. Please let me know how it works as I would like to know that everyone is getting the shared information. Thanks, Ken.

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John

10/25/2015 11:57:18 pm

This is so simple! I have never done any kind of casting before, so this seems like a safe first step and I'll definitely be giving it a try.

I bought a bag of water-based natural clay (I couldn't tell you the type, but it's a light gray color) a month ago with little understanding of what exactly I needed, intending to use it as a re-usable, air-hardening sculpting material.

I am aware that water-based natural clays tend to shrink and want to crack as they dry...so I am wondering, have you tried adding any sort of natural clay to this mixture? If so, what was the result? If not, I'll give it a try. I'll visit the store where I bought this clay and see if I can get some details about what exactly it was.

Thanks for any help!

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Ken

10/26/2015 03:20:52 pm

Hey John,
I have not added any other material to the mix as it does exactly as I wanted without modification. I am not sure what it is that you want to accomplish with the clay but by all means experiment and let us know how it goes. We all appreciate a shared effort to improve our ideas. Thanks, Ken.

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Sharon

11/11/2015 04:00:20 am

Hi Ken
This is really amazing. Been doing some testing and seems to be working well. Next batch I'm going to lessen the glycerine and see what strength I get.
Just want to know if you have a indication of the shelf life of the product?
I am using ozonated water which should prevent any mould forming etc.

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Ken

11/11/2015 09:40:24 am

Hello Sharon,
Typically, as the amount of glycerine is reduced, the material becomes stiffer. If you reduce it too much it will become extremely hard. It becomes very much like a cured epoxy. As far as shelf life, I have used it as many as 20 times with out any problem. If there is contamination it can be run through a sieve to filter out the contamination. I have not seen any mold over the course of a year using just distilled water so you should be fine. My best to you, Ken.

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Sharon

11/11/2015 10:35:00 pm

Thanks, what amount glycerine reduction would you recommend for a good firm mold? I'm thinking to try 20%?
Regarding Shelf life how long can the material be kept without using it eg if I make material and leave it before making a mold, can it be kept for 6 months or a year if not used continuously up to 20 times?

Ken

11/12/2015 09:48:29 am

Hi Sharon,
My apologies for not understanding the shelf life question. I have two molds that are at least two years old and still fine if kept at room temperature. So, there should not be a problem if the mold is protected from extreme heat. With regard to the glycerine I would try 30% and this is the reason: If the material is too hard you can add some glycerine to make it less stiff which is easier than trying to remove glycerine. And as mentioned, you can make this material really hard. I have not tried any experiments with the ultra-hard yet but it could be interesting. Thanks, Ken.

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Sharon

11/12/2015 10:14:18 pm

Thanks Ken, made a batch of 20% less glycerine and it is quite a bit firmer. I'm going to make another batch with 30% reduction and let you know which one works well. I'm intrigued now going to make a hard batch for the fun and see what happens. Thanks for the shelf life I thought maybe 1 year but it's good to know you've had for 2 years. Will let you know when all is tested. Thanks Sharon

Thanks very much for these directions and for all of the helpful comments regarding others' experiments and experiences. I'll be trying this kind of mold using a clear drying liquid acrylic medium as a casting material. Will see if I have the same situation as Marissa. I may only be able to use this process when adding a relatively opaque level of pigment to the medium, but it will still be a great tool in my studio.

BTW, I think this could also be used to create gelli plates that once damaged can simply be reheated to create a new gelli plate. Gelli plates are used for creating monotypes. If it is dense enough, it might be carvable like linoleum for linocut priontmaking as well. As I try these things I'll update you. This could be a VERY versatile material for artists!

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Ken

1/3/2016 10:28:23 am

Hi Rick,
I hope that your experiments go well and that you are able to expand our community knowledge. With regard to the gelli plate application I believe that the value may be in the fact that the Shore A hardness can be changed with the reduction of the glycerine. This make the gel possible to be carved or imaged. Thanks for the comments and thoughts, Ken.
.

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Rick Rogers

1/11/2016 11:23:11 pm

Hi again Ken,

For the typical gelli plate for monotypes, you will likely want to retain the completely flat surface, but still have a slightly harder surface. So I created one last night where I used less glycerine than your recipe, and it certainly looks to be an excellent gelli plate. I used the following recipe to make it somewhat harder and to make my calculations easier, since gelatin comes in 7g sachets up here in western Canada:
35 ml water
7g gelatine
30 ml glycerine (this would have been 42 ml with your recipe)
And it was a 10x batch that produced an 8"x8" gelli plate about 1/2" thick.

I'll wait a little longer before using it to try creating a simple monotype print, and then see how well it cleans up with acrylic paint. Then I'll carve into it and try making a relief print.

I hope to be a good community member and video tape these experiments, but I'm inexperienced with a video camera and lighting, so we'll see how it turns out before I post it on YouTube...

Cheers!

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Ken

1/13/2016 09:44:06 am

Hey Rick,
I appreciate the fact that you are keeping us in the loop and hope for success. I have thought about flat surfaces and thought that a glass plate with sides might work well with the glass surface being the top of the mold. How do you get a flat surface? Keep us informed and good luck, Ken.

Rick Rogers

1/14/2016 10:45:59 pm

I had something already available to me, a cheap 8" square silicone cake pan that I got at a clearance store a while ago for use in the studio. But I am sure that a casserole dish or a piece of glass and a dam of modeling clay would work well too.

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Rick Rogers

1/17/2016 01:22:37 pm

Hey Ken,

The test of the printmaking plate application went very well overall. The recording not so much, so I won't be posting a video as planned.

Anyway, here are the findings:

1. The firmer material was excellent for a gelli plate. It accepted marks from paint brushes, a brayer, a paint marker, and fingers readily, and released the acrylic paint to paper really well, so it makes a great monotype printmaking plate.

2. It cleans up like a dream. A little water and it comes right off the plate, leaving only miniscule dots of acrylic in micro-bubbles on the surface of the plate. These little dots don't impact the prints pulled from the plate at all.

3. The one negative result was that bending it while carrying it around - mostly to and from the sink for cleaning - caused the surface to rip/split/crack and with repeated manipulation the rips continue to deepen and widen, as you'd expect. (But it can always be remelted and recast!)

4. Since it was ripped already, I also tried carving it like a lino plate. It carves really easily with a knife, but not well at all with carving tools. The initial cut tends to rip with carving tools because the plate isn't firm enough for a v or u shaped blade to slice into it without deforming it first. Perhaps if I REALLY sharpened my tools... but I have some ideas for creating a reusable relief printmaking plate from it.

5. The print pulled from the relief carving was great. I only tried it with acrylic paint, but the paint rolled onto it very nicely and the pulled print had nice sharp edges where the cuts were made.

So a follow-up question for you: Does the tear strength of the material come primarily from the gylcerine or the gelatine? If I reduce the glycerine further, do you think it will become even more likely to rip as I expect? And if so do you have any suggestions for other plasticizers that might allow a firmer plate that doesn't rip easily? In some initial searches online, I found references to sorbitol, cirtic acid, cooking oils and vinegar being used with bioplastics as plasticizers, but no clear information on what the differences and what ratios make sense. I think this might warrant a trip to the library sometime soon to understand the chemistry behind it more.

Cheers,
Rick.

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Ken

1/18/2016 11:04:48 am

Hey Rick,
It certainly sound promising so far as you have indicated. The tear strength seems to come from the gelatin and the glycerine allows mobility for the gel. So, my best guess without experimentation is that the tear strength will increase as the glycerine is reduced. Your dilution was quite moderate so a further reduction may be actually better. But a better solution may be in simply chilling the plate before cutting. The Bloom Test (gel strength) is performed at 10 C so cutting might be better and cause less tearing at cooler temperatures. And although there are other plasticizers available, at this point there does not be an advantage to using them yet. Referring to the Bloom Test, the normal unflavored gelatin has a rating of about 225. However, there are gelatins available with higher ratings that may be considered at some point. I found the following link to the "Gelatin Manufactures Handbook" that you can copy and paste to get to the PDF. It is a complete chemistry of the gelatin collagen relationship and physical characteristics. Ken.
https://www.google.com/webhp?gws_rd=ssl#q=bloom+strength+of+gelatin+pdf

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Ken

1/18/2016 11:13:14 am

Rick,
That link was incorrect. Try this instead: https://www.google.com/webhp?gws_rd=ssl#q=handbook+of+gelatin

Ken

1/18/2016 11:19:08 am

Rick,
I am not sure why these links are not working so just go the Google and use Gelatin Handbook as the search term. It works! Ken.

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Rick Rogers

1/18/2016 01:01:10 pm

Thanks Ken. That reference is helpful.

Two further results:

1. Cleaning is even a breeze a day later with paint that was marked on the surface of the plate. A little water and rubbing and even dry feeling acrylic paint comes off.

I'll melt this plate, add more bloomed gelatin, and recast it to see if an even firmer plate will hold up better to the monotype process And I think I have a great idea for a relief printmaking process as well, once the material is a bit firmer. Will try that with and without the cooling suggestion - thanks!

2. Unfortunately though, I think I've determined why the cleaning was so easy. When it came to the acrylic casting test, this material ran into several difficulties. An acrylic skin (poured acrylic medium mixed with liquid acrylic paint) was very slow drying, compared with it's usual drying time. Basically the acrylic stays wet underneath a very very long time.

The edges of the plate even started to turn upward away from the table it was on. Acrylic is a water-based polymer that cures through the process of evaporation, drying from the top down. I think that the acrylic skin poured over the cracked and cut area of the plate was absorbing water from the plate itself while its own water was evaporating off during the curing process. Not sure how to prove this, but I am quite certain that acrylic in liquid state, and perhaps even thickly applied gels will not cure effectively as reliefs when poured over a carved plate of this material. I suppose it is possible that the ripping and cutting of the plate may be the problem, so I might try casting again, but in an undamaged mold to see if the problem persists. But I suspect that casting with liquid acrylics may always have this problem.

I wonder whether using hydrophobic plasticizers or a hydrophobic plasticizer and water, instead of glycerine and water might help, but then I'm not sure how the liquids would mix effectively enough to plasticize the gelatin. A problem for a more dedicated scientist!

I may be stuck with silicone (not reusable) for casting acrylic, but this material should work well for casting epoxy resins. Onward!

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does it smalles like rubber??

2/21/2016 11:20:03 am

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Ken

2/21/2016 05:27:29 pm

No.

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Ella Jameson

3/9/2016 10:35:58 pm

I'm looking to cast some ABS parts in Silicone. I'm totally new to this, so I'm bound to make mistakes. My casts will be mainly one-offs, so a reusable mold solution is promising. One that's so cheap and easy is also attractive. However, I would appreciate some advice.

I don't have a degassing chamber, so I'm likely to use Mold Star 20T with some pigments added. I am currently planning on using Ease Release 200 for the mold release, but I'm open for any suggestions.

From what I've read, it doesn't seem that silicone exotherms much at all, so my initial reaction is to say this might work will. What do think?

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Ken

3/12/2016 09:53:59 am

Hi Ella,
Unfortunately I am not sure that I understand the question. If you are going to cast ABS in a silicone mold, how does the reusable molding material play a part? If the mold is silicone, it should not need a release agent for most polymers being cast. Please explain more. Ken.

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Ella Jameson

3/12/2016 05:18:31 pm

No, I mean I want to create a copy of an ABS part that's made out of silicone. So the work flow would look like this:
ABS positive > reusable mold negative > silicone positive.

I know that making the mold of the ABS part out of the reusable material works, as I've tried it a few times and it's worked. What I want to know, preferably before potentially wasting material, is if casting silicone into this mold will be likely to work.

As another area of interest, I've noticed that there are a ton of bubbles that form on the surface of the part being molded. Are there any techniques to eliminate this? I know Composimold (basically a commercial version of this stuff) sells a 'Bubble Buster' solution that lowers surface tension. Do you know of anything cheaper I could use/make that would act like that?

Ken

3/13/2016 09:37:56 am

Hey Ella,
Thank you for the clarification as it is now clear. The silicone in the reusable molding material should be fine but I would probably chill the mold as the silicone is mildly exothermic as it cures but the chill is not essential. But, it will be somewhat firmer and perhaps more stable. As far as the bubbles I find that the bubbles appear in non-active areas of the mold, particularly at the top. But a small amount of isopropyl alcohol or even dish washing detergent in very small amounts may help. Pouring slowly also helps. It is viscosity as much as reducing surface tension. Please keep us informed as you experiment. Thanks, Ken.

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Deborah

11/2/2016 02:11:52 pm

Hi Ken,
From my old jello making days, bubbles could be gently scooped off the surface with a spoon. Obviously unnecessary functionally for moulding, bubbles just interfere with my chi-ha!

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Elizabeth

4/16/2016 10:34:47 am

Ken i have a broken yard angel. Can i make a mold like this to make a plaster wing from the good wing using plaster paris

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Ken

4/17/2016 10:53:07 am

Hi Elizabeth,
Depending on the size (amount of material) it should wok just fine, I have used it to repair other plaster objects. Ken.

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Johnny

5/15/2016 11:46:18 pm

Hi Ken, have you tested using this Mold-material for casting resin Parts?
Maybe we can discuss some further tests as I did some already myself, I'm looking for a good release Agent. I'd also like to know about your experiences an faybe freezing the Material.
BR

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Ken

5/16/2016 09:13:36 am

Johnny,
As shown in the videos I have cast epoxy and polyester successfully and in most situations I use silicone spray as the release agent. I have not had an occasion to freeze the material so I cannot comment. Thanks, Ken.

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Sharon

6/29/2016 11:18:07 pm

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Ken

6/30/2016 09:03:08 am

Sharon,
Please resubmit your comment. Ken.

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Sharon

7/12/2016 11:27:58 pm

I only resubscribed as I accidently unsubscribed thanks

John

7/11/2016 07:50:27 pm

Hi Ken. 2 questions. I am moulding polyurethanes with exotherm temps higher than 130 F. Any suggestions for an additive to increase the mold-material's melt temp? Also...is it possible to de-gas the mold-material in a vacuum chamber prior to casting the mold?
Thanks!

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Ken

7/12/2016 03:18:40 pm

Hi John,
I have successfully cast polyurethane as well as epoxy and polyesters by simply chilling the mold. I can not think of any useful additive but you could reduce the amount of glycerine which reduces the flexibility but raises the melt point. But, I would not reduce it more than 15 or 20%. And yes, you can degas the melt prior to casting. I have even had good luck with one of those hand vacuums. Thanks for the questions, Ken.

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Becky Hall

7/19/2016 11:55:41 am

Alright guys!
I have never had a problem with this material I have cast with amazing resin and I also pour easy cast and castin crafts in it I make miniature toy replicas so for the hard to find ones I actually sculpt them in clay myself and then cast them in the gelatin I then pour them in the resin fine-tune them afterwards by sanding and then repour them for my final cast. This is a very long and drawn-out process that's what I like this material because this material is reusable. I did this and I poured molds and about a month later I ended up going back to using my mold and it has shrunk 50% now I was sitting on here looking up how to reproduce result as it captured all the detail of my larger sculptures but reduced it 50% and I remembered that I put rubbing alcohol into my mixture to help for some of the bubbles cuz I had overheated it and cause a lot of foam on top so I'm guessing what happened was when I added the alcohol to the mixture it filled it and acted as a filler and then over time the alcohol dissipated or evaporated which shrank my molds happy accidents

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Ken

7/19/2016 04:38:12 pm

Hi Becky,
Interesting post as it raised some good questions. First, the over heating probably caused some water to be driven off. Second, the alcohol forms an azeotrope which makes the water easier to evaporate. All water based colloids will release water over time so it may be useful to cover and refrigerate. Additionally, it may be worth weighing the material to see if waster has been removed and replace it. A final thought is that a hand vacuum pump might be helpful in removing bubbles as they are cheap and easy to use. Simply make a mason jar or other suitable container as the vacuum vessel and then pump for a partial vacuum. Walmart has one but others are easy to find. Thanks, Ken.
http://www.walmart.com/ip/American-Educational-Products-7-206-2-Vacuum-Pump/48013328?wmlspartner=wlpa&sele

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Ken

7/19/2016 04:43:37 pm

Becky,
The link failed to work so just Google "hand vacuum pumps". Ken.

Adrian

9/6/2016 04:32:47 am

Hi,
I was wondering how this recipe worked as a casting agent?
I have found a few posts sharing this, or a similar recipe for making moulds but I am looking for a safe home made recipe for casting..

If I already have moulds of the figurines I want to duplicate, how effective and durable will this Gelatine/Glycerine mixture be if I wanted to use it to make the actual casts out of?
I need it to be relatively firm but still flexible and not something that will break, tear or disintegrate over time (like silicone except that silicone is expensive and hard to come by where I am - Food grade, non toxic silicone that is).

I want to make some soft figurines/toys that are safe for kids.

Any advice?

Regards

Reply

Ken

9/6/2016 09:46:10 am

Hi Adrian,
My best advise is that this material is not really suitable as a casting material. I think that for the purposes that you describe a polyurethane might be a good choice. Copy and paste the link to Tap plastics for some good alternatives. Thanks, Ken.
http://www.tapplastics.com/product/mold_making_materials/casting_products/tap_quik_cast/74

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Adrian

9/6/2016 12:36:16 pm

Thank you for your reply Ken,

I have had a look at the link provided, unfortunately this will not work for my intentions, I am looking for something that will be "rubbery" when set, like silicone. It will also need to be non-toxic or food grade as I intend on making casts of children's toys...
Considering the fact that small children tend to put just about everything into their mouths it will have to be safe and non-toxic.

There are certain types of silicones available that are suitable but they are not available where I live and will cost a penny to order. I was just wondering if there was a homemade solution for this.

It does not need to last a lifetime, as long as it does not break or fall apart easily and maintains the shape that it is cast to.

If I were to try this solution out, just for interest sake, what would you recommend as a good ratio to be sure the end result gives a soft yet firm rubbery finish?

I will look into something more suitable when I have more to spend and more experience with what I am planning to make, this will be a temporary solution to see what can be done.
Do you think it might be possible to get a good result using your recipe, considering all the above mentioned criteria? Once again it does not need to last a lifetime, just not be broken too easily.
Also what could I use to make the final results different colours? Will food colouring work for this? will it set with the solution or will it stain?

Regards

Ken

9/7/2016 03:11:34 pm

Adrian,
They do make urethane that is flexible but the safety issue would be a problem. At the moment I can't think of an alternative but I will give it some more thought. To try my process I would suggest a small experiment where you reduce the glycerine by 25 %. This would give you an idea how flexible vs. hardness it can be. Adjust from there. As far as color, since it is starting out as amber, adding color might be less desirable than you want but it is worth a try. Let us know how it works. Good luck, Ken.

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Ken

9/7/2016 03:59:18 pm

Adrian,
After I posted the above response I was thinking about using bio plastics in your application. It is food safe and can be make flexible with glycerin, and can be colored with food color. I have made several types using corn starch and it may be worth looking at for your project. I did a little research and found an Instructable to check out. They used potatoes but also includes the use of corn starch which is easy to find. Check out the following link and copy/paste. Ken.
http://www.instructables.com/id/Make-Potato-Plastic!/?ALLSTEPS

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Jack Wood

9/9/2016 07:13:02 am

One thing I noticed is that the mould will sag after a couple of days at room temperature. For example the candle moulds I left here by the computer out of direct sunlight after a few days have turned into bent candle moulds even though they are an inch thick either side of the candle! I think with some extra gelatine it might hold it's shape better!

Reply

Ken

9/9/2016 09:57:21 am

Hello Jack,
The problem you report is of course due to the relatively low melting point of the material and the effective wall thickness. Additionally, the high RH in summer can increase the tendency to sag or deform. And, you are correct that the ratio of gelatin/glycerin is the important issue. As in previous posts, I recommend a reduction in glycerin to increase stiffness. I have added gelatin to a prepared mix but it is really a PIA. The gelatin has to be in a water solution and is tricky to get right. In your situation I would probably recast the candles with an increased wall thickness and make any subsequent batches with maybe a 10 % reduction in glycerin. Just a thought. Thanks for the comment, Ken.

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Jack Wood

9/9/2016 10:23:46 am

Thanks for the thoughts! If I try it I'll report back

Michael

10/9/2016 03:40:36 am

Hi Ken,

Thanks for all your hard work in posting on this project! I tried my first batch today and it was very straight forward following your instructions. The only problem I have is that the tear strength is quite low. I wasn't able to remove the master without wrecking the mould...

The recipe I used was:
100 mL each of water and glycerine
20 g of gelatine

Any suggestions? Given that I am already using less glycerine than your base recipe I am wondering whether I need to increase the amount of gelatine?

Cheers,

Michael

Reply

Ken

10/9/2016 04:42:52 pm

Hi Michael,
I would agree that a closer approximation of glycerin to my original formula would be helpful as more plasticizer eases the tearing. But, since the gel is a colloid the structure will have a tendency to tear. However, if you noticed in video two when I took the Santa Clause figure out, I really beat the mold up and it still didn't tear and that figure had a lot of undercuts. The molding is clearly not a replacement for RTV silicone but it does have utility as well as some frustration. Hope that this helps, Ken.

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Michael

10/10/2016 03:55:50 pm

Hi Ken,

Thanks for your quick reply. While I was never expecting RTV performance, I was impressed with what you were achieving in your videos and wanted to try and replicate it. My first "base" recipe (as posted above) appeared to be both less stiff and less tear-resistant than yours, so I wanted to experiment a bit further.

Here's how I went about it: I remelted what I had and divided it into 4 portions:
A) the unaltered base recipe.
B) the base recipe + 10 mL glycerine.
C) base + 2 g gelatine (hydrated with 15 mL water).
D) base + 10 mL glycerine + 2 g gelatine (15 mL H2O).
I mixed/heated each recipe, poured each into a small round dish and allowed to set overnight. I then demoulded the samples and did a rough elongation test to see how far they would stretch before breaking.

Observations:
As you would expect, the addition of gelatine produced a firmer consistency and the glycerine increased elasticity.

"Results" (really rough, so take with a grain of salt):
B elongated 10-15% more than A before tearing.
C elongated to a similar length as B but did not tear.
D elongated 5-10% more than A before tearing.

Conclusion:
I need to increase the amount of gelatine in my recipe to improve the tear strength. I wonder whether it has a lower bloom strength than the gelatine you are using? (There is nothing marked on the packet, so I can't compare numbers). Adding glycerine as well may or may not be necessary. I expect there is a trade-off between elasticity and tear strength - the "sweet spot" will vary depending on the shape being moulded (e.g. one would probably want more glycerine if there are large undercuts).

I have now mixed all the samples back together (it's great how reusable this is!) and will try moulding the same pattern I tried last time. Will let you know how it goes.

Cheers,

Michael

karri

11/28/2016 01:28:52 am

I don't see the videos or any links, possibly because I'm on my mobile? I'm not sure, but I wanted to watch then before doing this. Also, what are your thoughts on using this for fine detail wax casting? I've been fiddling with plaster molds without much luck. It holds the detail wonderfully, but always breaks when coming out. Lastly. .. Could you make a mold a using s |6l kipsculpted from clay, such as plastcine?

Reply

Ken

11/28/2016 10:18:04 am

Hi Karri,
I am not sure why you are not seeing the videos as my site supports mobile devices. Could be in your video application as I have not had this report before and they work on my mobile devices. I will post a YouTube link below to copy and paste for an overview and video 1. In video 2 I show the use of paraffin wax and it works very well. I really can't respond to clay or Plasticine as I have not tried them at all. Please let me know if I can be of further help, Thanks, Ken.
https://www.youtube.com/watch?v=u3lLyDnWUxE

Reply

karri

11/28/2016 04:01:03 pm

I am having trouble loading the 2nd video, for some reason. So if you discuss clay.. But can you please tell me if I would be able to make a mold using plastcine clay as the model?
Do you think i should make a plaster cast of the clay item to use as a model with this reusable material. .. I'm new to this and so i appreciate any advice you might have thanks karri

Reply

Ken

11/28/2016 05:25:40 pm

Karri,
The problem with Plasticine is that it will soften with the molding material so a plaster casting would be best. As far as the video, I have tried to fix the problem but find that there is a difference between cell and WiFi so I'm not sure how to fix your problem. I could copy the video and send it to you via Google drive but it will take a little time. Send me your email and I will do what I can. Ken.
ken.quast@gmail.com.

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Devin

12/21/2016 04:06:40 am

Nice but does it work with plastic or any hard materials?

Reply

Ken

12/22/2016 05:39:04 pm

Hi Devin,
I am not sure what your question is and can you explain further? Thanks, Ken.

Thankyou Ken for your expertise. I find that this recipe is just as good as the commercially available Composimold but much cheaper. I have probably cast 6 or 7 times with minimal air bubble sign then remelted and cast something else. Durability of mold also depends on medium that is used to cast and how well mold is cleaned after casting. I have yet to experience any mold forming in over 1 year just shrinkage over time. The mold release spray I use with great success is Pam cooking spray but this time I want to try a new batch with alcohol sprayed on the item to be cast ad my Bubble buster. I have cloned many miniatures using this method and look forward to cloning many more.
Thanks again and well done sir.

Reply

Ken

1/30/2017 03:39:16 pm

Hey John,
The use of Pam sounds interesting and the alcohol is a great idea for a bubble disrupter. Thanks for the added knowledge and comments, Ken.

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sebastian

1/30/2017 09:47:55 am

Hi Ken, I've tested your recipes and it worked great! I have a nice very clear mould (my gelatine is not colored).
Thank you for the clear and simple recipe.

I also struggle with the stiffness.
Do you think some other products could help to make a more resistant mold?

I've seen alternative recipes that included corn syrup/honey (glucose), or denatured alcool (don't know what that is), I also read that a bit of acidity could make gelatin stiffer, maybe a bit of dissolved lemon juice could do something?

I have some composimold and its very stiff while still transparent. Its has a weird smell, some kind of fruit juice maybe (that's why I was thinking to honey or lemon...)?

Reply

Ken

1/30/2017 03:45:47 pm

Hi Sebastian,
The easiest way to decrease the flexibility is to decrease the glycerin. Try a 20 % reduction on a small sample and you can go from there. I would be cautious about adding any of the materials that you mentioned as they will present a mold problem. Thanks for the input and comments, Ken.

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Ayry

3/27/2017 12:38:20 pm

I have seen that to get rid of the bubbles you can just spray it with rubber alcohol

Reply

Ken

3/29/2017 04:05:59 pm

Ayry,
That is true just use enough isopropyl alcohol to break the bubbles. Ken

I'm trying to shrink my gelatine casts. How do I mix ispropanol into the mix as I understand this may be the key to the shrink. If this is possible will it shrink proportionally.Any help would be fantastic. Mike

Reply

Mike Burrett

5/6/2017 04:14:36 am

Ps. That should read isopropyl.

Reply

Ken

5/6/2017 10:12:24 am

Hey Mike,
Both isopropanol and isopropyl alcohol are acceptable so either way you are correct. As far as shrinking the gelatin, I am a little skeptical that it it a good way to do so. IPA works to dehydrate or remove water and it is compatible with both glycerine and water but will volatilize at higher temperatures. A better way to do it would be to just let it air-dry or put it in a reduced vacuum. I believe that IPA will only give you about 1 to 2 % shrinkage if used at 5 % of the total liquid needed. If you have better sources of information please share them with us as I can always learn something new! Thanks, Ken.

Thanks Ken, I will notify you of any finds. A few years ago I was working on a bio- degradable ball. The ball cast well and withstood impact when hit. The only problem was when used in the damp the glycerine became soapy. Is there anyway to waterproof the cast.
I mixed calcium into the mix to add a nice solid colour. I did also read somewhere the zinc improves tear strength, I may have used this, I cannot remember. The ball was stored in a plastic bag and is still in fine condition (at least 2 years later). I would love to find a Vegan option, but agar did not perform so well.

I am the owner of the website Candle Needs (http://candleneeds.com/). My website provides information for people who are looking to either make or buy candles for great deals. I was browsing through and your website caught my eye. I really like your website and the great information you provide for your visitors.

With that being said, I was wondering if you would be interested in exchanging links. I would be delighted to do this, so please let me know if this is something you would be interested in.

To reach me, please contact me through the contact page on my website.

Thank you & have a great day.
Talk to you soon.

With Sincerity,

Steve

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LM

5/24/2017 04:11:18 pm

Sending appreciation for the thoroughness with which you provide fascinating information, especially regarding SAFETY instructions, cautionary notes, and helpful suggestions. You demonstrate great patience with all the commentary across the few videos and experiments I've read through, thus far, showing commitment to the spirit of open source sharing. :D

Reply

Ken

5/25/2017 04:08:32 pm

Hi LM,
Thank you for your kind and generous words. Six years ago when I started this site I was hoping for readers/viewers that would appreciate simple and open source material and I have not been disappointed. I will continue as long as I can. I value your opinion and thanks, Ken.

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Bran

6/13/2017 10:53:19 am

Hey Ken:
I've mixed a few small batches of the material using your recipe but mine aren't quite turning out like your's is (or other's I have seen). In the mix, there are what looks like very tiny bubbles suspended. The first batch I did definitely had bubbles (which I think came from heating it in the microwave too long and also stirring it too rough). In the second batch it almost looks like it's particles of the gelatin floating around in it rather than tiny bubbles. I let it cure and almost 2/3 of it was foam-like and floating on the top. Also, I don't know if it helps, but my mix is a light tan (almost khaki) rather than a orange/brown I've seen with other's. I am using Knox gelatin, too.

Do you have any advice you can provide on this? If it is just suspended particles of gelatin, is adding more water to dissolve it okay or will that affect the material?

Reply

Ken

6/13/2017 05:19:04 pm

Bran,
It certainly appears to be undissolved gelatin that is causing the problem. That is why I would suggest making the first batch on the stove as in the video. Dissolution is complete and quick. Subsequent melting is fine in the microwave. Thanks, Ken.

Reply

Laurie

7/30/2017 12:52:34 pm

Would these molds work with melt and pour soap?

Reply

Ken

7/30/2017 03:36:26 pm

Hi Laurie,
This is a difficult question to answer but it may be worth trying a small amount. As the video shows, I have poured paraffin wax and that has a higher melt point than the soap. But, the mold has to be cooled in the refrigerator before the pour. However, most melt and pour soaps have glycerine and that would be possibly destructive to the mold. If you do try it, let the soap get hard before removal. Pulling it out soft may cause damage to the mold. Sorry that I can't be more definitive. Good luck, Ken.

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The author has an eclectic background in chemistry, electronics, writing, mental health, and community action...Ken